Human hair becomes soiled due to its contact with the surrounding atmosphere and, to a greater extent, from sebum secreted by the head. The build-up of sebum causes the hair to have a dirty feel and an unattractive appearance. The soiling of the hair necessitates it being shampooed with frequent regularity.
Shampooing the hair cleans by removing excess soil and sebum. However, the shampooing process has disadvantages in that the hair can be left in a wet, tangled and generally unmanageable state. Shampooing can also result in the hair becoming dry or "frizzy" due to the removal of natural oils or other hair moisturizing materials. After shampooing, the hair can also suffer from a perceived loss of "softness". Softness, of course, is a generally desirable attribute for many users of shampoo products. A variety of approaches have been developed to alleviate the after-shampoo problems. These range from the inclusion of hair conditioning aids in shampoos to post-shampoo application of hair conditioners, i.e., hair rinses. Hair rinses typically work by depositing a polymeric film, cationic hair conditioning surfactant, or other material onto the hair. However, such solutions to a very prevalent problem have not been fully satisfactory. For one thing, hair rinses are generally liquid in nature and must be applied in a separate step following the shampooing, left on the hair for a length of time, and rinsed with fresh water. This, of course, is time consuming and is not convenient.
While a wide variety of shampoos have been disclosed which contain conditioning aids, conventional executions of these have not been totally satisfactory for a variety of reasons. A prevalent problem relates to compatibility problems between good cleaning anionic surfactants and the conventional cationic agents which are good conditioning agents.
Silicones are materials which can provide excellent hair conditioning benefits and which are not incompatible with anionic detersive surfactants.
Silicones in shampoo compositions have been disclosed in a number of different publications. Such publications include U.S. Pat. No. 2,826,551, Geen, issued Mar. 11, 1958; U.S. Pat. No. 3,964,500, Drakoff, issued Jun. 22, 1976; U.S. Pat. No. 4,364,837, Pader, issued Dec. 21, 1982; and British Patent 849,433, Woolston, issued Sep. 28, 1960. While these patents disclose silicone containing compositions, they did not provide answers to all of the problems encountered in making a satisfactory product. One problem is that of keeping a dispersed, insoluble silicone material suspended and the total product stable. Recently, stable silicone-containing hair conditioning shampoos have been described in U.S. Pat. No. 4,741,855, Grote and Russell, issued May 3, 1988, which discloses shampoo with cleaning surfactant, an insoluble, non-volatile silicone, water, and a suspending agent such as long chain esters of ethylene glycol, esters of long chain fatty acids, long chain amine oxides, etc. Stable silicone-containing hair conditioning shampoos have also been disclosed in U.S. Pat. No. 4,788,066, Bolich and Williams, issued Nov. 29, 1988, which discloses a xanthan gum suspending agent.
Stable, silicone-containing hair conditioning shampoos have recently attained substantial success in the marketplace. These shampoos can provide excellent hair conditioning benefits to the user. However, it would be desirable to improve these types of shampoos by increasing the efficiency of the silicone hair conditioner incorporated into such shampoo in order to reduce the amount of silicone that is incorporated into the shampoo and, consequently, to reduce raw materials cost. One factor affecting effectiveness of the silicone hair conditioner is the ability of the silicone to deposit upon the hair.
It is an object of this invention to specifically provide silicone hair conditioner-containing shampoo compositions characterized by improved silicone hair conditioner deposition upon the hair.
Unless otherwise indicated, all percentages are calculated by weight of the total composition and all ratios are calculated on a weight basis.